STRAWBERRY MILKSHAKE: Radiator/ Transmission Failure (automatic transmissions only)
While it is a rare occurrence, the most notorious and costly of the known issues is by far, the “strawberry milkshake.” Also known as the ‘pink milkshake’, the cause of the issue is in the pipes in the lower part of the radiator that cools the transmission. The lines are known to corrode and allow the mixing of engine coolant and transmission coolant fluids. The root of this corrosion is from the buildup of minerals in the radiator, regular coolant flushing is a good way to slow this buildup.

When the two fluids mix, the mixture overflows into the coolant overflow reservoir with a fluid that looks a lot like a strawberry milkshake (may be a different color if you dont have TOYOTA red coolant..). If the mixture manages to return to the transmission, it can cause catastrophic damage. Often resulting in a ruined transmission. When a milkshake strikes, you will notice your transmission will not want to shift or hold a gear when moving.

-As stated above, this will only happen to trucks with automatic transmissions. This typically starts to become a concern when the truck gets to be about 8-10 years old. Or even sooner if it is a rusty truck.